Quiz Questions for the USMLE

 

Preparing for the United States Medical Licensing Exam Step 1, 2 or 3 is difficult, time-consuming, and anxiety-provoking. Knowing the information cold is the best way to ace the test. Although the test is multiple-choice, studies have shown that being able to answer unkeyed questions shows a higher level of mastery of the material. Try these to see how you are doing...
Question 1
A mildly mentally handicapped 31 year old male is noted to have 10 café-au-lait spots greater than 2 cm, pigmented iris hamartomas, and multiple peripheral nerve Schwannomas. What enzyme is lacking?

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GTPase

This is von Recklinghausen’s disease
The defect is on chromosome 17

Question 2
If a patient has increased histamine release, venous telangiectasia, bronchoconstriction,
and edema, what is the best test to confirm the diagnosis?

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24 hour Urinary 5-HIAA

This is carcinoid syndrome
Lab findings in carcinoid syndrome include:
Increased urinary 5-HIAA
Increased urinary histamine
Increased serum bradykinin
Increase peptide P substance

Question 3
A 17 year old girl has abdominal pain, sweating, headaches, and black urine every time she consumes alcohol. What enzyme is decreased?

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HMB synthase (PBG deaminase)

This is acute intermittent porphyria
Other gastrointestinal symptoms in acute intermittent porphyria include:
Ileus
Distention
Nausea
Vomiting
Constipation
Diarrhea

Question 4
A 72 year old man has swelling and pain in his left great toe joint which developed over
12 hours. There is no fever or other constitutional systems. What is the best drug to treat this condition?

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Indomethacin

This is gout
Other drugs used to treat gout include:
Colchines between attacks
Allopurinol
Uricosuric drugs – probenecid, sulfinpyrazone

Question 5
A 28 year old man was taken to the operating room for an abdominal obstruction where it was discovered that his ileum contained four 1 cm smooth, submucosal nodules that were yellowish tan on the cut surface. What is the most likely diagnosis?
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Ileal carcinoid

30% of ileal carcinoids are multicentric
Anatomic distribution of abdominal carcinoids is:
Appendix – 45%
Jejunum-ileum – 28%
Rectum – 16%
Colon – 2%
Ovary - 1%

Question 6
If a patient has coarsened facial features, prominent supraorbital ridges, large, spadelike hands and feet, soft tissue proliferation and an enlarged sella, what substance is most likely to be secreted in excess?

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Growth hormone

This is acromegaly
Microanatomy of acromegaly includes:
Well-defined pituitary adenoma – most commonly in lateral wings of sella
Adenomas very rarely in sphenoid sinus or parapharyngeal regions
Ectopic production rarely in pancreatic islet cell tumors or lung tumors

Question 7
If a 6 year old girl has hemorrhagic diarrhea, rapidly progressive renal failure and purpura, what two microorganisms are the most likely cause?

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E. Coli (serotype 0157:H7)
Shigella dysenteriae

This is hemolytic uremic syndrome
Other signs and symptoms include:
Fever
Pulmonary edema
Seizures

Question 8
A 54 year old man finally died of his progressive dementia after a 15 year course. He had choreoathetoid movements in the last two years. What is the cause of this disease?

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Excessive repeat of the CAG nucleic acid sequence

This is Huntington’s chorea
Presenting sign of Huntington’s chorea is striking emotional changes years before choreoathetoid movements

Question 9
A 65 year old man has an oat cell neoplasm of the lung. He develops total body edema, lethargy and confusion, and nausea. Overproduction of what substance is the likely cause of this condition?

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Arginine vasopressin (ADH)

This syndrome of inappropriate antidiuretic hormone secretion (SIADH)
Other signs and symptoms of SIADH include:
Headache
Seizures
Can be asymptomatic and picked up only by low serum sodium

Question 10
If a patient has paroxysmal hypertension, sweating, palpitations and nervousness, and headache, is she more likely to be hypoglycemic or hyperglycemic?

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Hyperglycemic

This is pheochromocytoma
Lab findings in pheochromocytoma include:
Hyperglycemia
Increased serum epinephrine
Increased serum norepinephrine
Increased metanephrine
Increased VMA

Question 11
A 24 year old man has bilateral anterior conical displacement of the lens, hearing loss, and renal insufficiency. What is the characteristic gene defect?

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Defect in type 4 collagen alpha-5 gene

This is Alport’s disease
Bilateral anterior conical displacement of the lens is called lenticonus and is pathognomonic for Alport’s syndrome.

Question 12
A 21 year old man develops low back pain with progressive stiffness and later develops pain in his shoulders bilaterally. Serum tests for rheumatoid factor are repeatedly negative. What is his most likely HLA type?

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HLA-B27

This ankylosing spondylitis
90% of patients with ankylosing spondylitis have HLAB-27 but only 1% of HLA-B27 patients develop ankylosing spondylitis.

Question 13
A 47 year old woman pulls a tick off her back and 48 hours later notices at the tick site a erythematous ring of tissue that slowly expands over the next several days. She also develops a fever and headache. What 4 infections are considered coinfections with this disease?

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Ehrlichiosis (both granulocytic and monocytic variants)
Babesiosis
Bartonella
Mycoplasma

This is Lyme disease
The most common causative agent of Lyme disease in the United States is Borrelia burgdorferi.

Question 14
If a patient has purple striae, muscle atropy in the upper and lower extremities, borderline diabetes, and menstrual difficulties, is the patient more likely to be hypokalemic or hyperkalemic?

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Hypokalemic

This is Cushing’s syndrome
Lab findings in Cushing’s syndrome include:
Increased plasma cortisol
Increased urinary cortisol
Increased urinary 17-hydroxycorticoid
Hypochloremia
Metabolic alkalosis

Question 15
A 68 year old man has the onset of angina and then in the next 6 months develops syncope and congestive heart failure. What is the most characteristic finding observed when the patient’s carotid artery is auscultated?

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Pulsus parvus et tardus (slow, prolonged rise in pulse)

This is aortic stenosis
Aortic stenosis becomes symptomatic when the cross-sectional area of the valve is < 1.0 sq cm

Question 16
If a patient has hypertension, metabolic alkalosis, and hypokalemia, what substance has excess secretion?

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Aldosterone

This is Conn’s disease
Physiology of Conn’s disease includes:
Increased sodium reabsorption with exchange of potassium and hydrogen
Diastolic hypertension
Extracellular volume expansion

Question 17
A 50 year old white male presents with abdominal pain, fever, skin pigmentation and arthritis in his shoulders bilaterally. The endoscopic biopsy shows flat and thickened villi and a small, gram-positive rod. What is the best treatment for this patient?

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Trimethomprim-sulfamethoxazole (Bactrim) for 1 year

This is Whipple’s disease
Other signs and symptoms of Whipple’s disease include:
Anemia
Pericarditis/endocarditis
Lymphadenopathy
Hepatitis

Question 18
A previously normal 4 year-old boy seems to have lost muscle strength in his shoulder area, but has developed overly muscular calf muscles with contractures in his heel cords affecting his ambulation. What substance is most likely missing in his muscle fibers?

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Dystrophin

This is Duchenne’s muscular dystrophy
Histology of Duchenne’s muscular dystrophy includes:
Breakdown of sarcolemma
Degeneration and necrosis of muscle fibers
Type 1 and 2 muscle fibers attempt to repair and regenerate with fibrosis

Question 19
A 72 year old female has pain in her right thumb and index finger. An arteriogram shows a non-obstructing “pipestem” lesion in the right radial artery. What layer of artery is most likely normal in this condition?
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Intima

This is Monckeberg’s arteriosclerosis
Most typically affects medium-sized muscular arteries

Question 20
A 58-year old female has recurrent angina with left chest pressure and jaw pain. She has three cardiac catheterizations in the last 8 months with completely normal anatomy and no obstructive lesions. Are these episodes of chest pain more likely to occur during exertion or rest?

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Rest

This is Prinzmetal’s angina
Attacks tend to occur at same time of the day for unknown reason.

Question 21
A 67 year old male has striking splenomegaly, recurring bacterial infections, recurrent epistaxis, and development of a warm antibody hemolytic anemia. What is the most characteristic cell seen on peripheral blood smear?

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Smudge cell

This chronic lymphocytic leukemia (CLL)
95% of cases are B-cell in origin.

Question 22
A 28 year male was noted on physical exam to have a blood pressure of 200/100. On further investigation he was found to have blood in his urine, a creatinine of 3.2 and enlarged, palpable bilateral flank masses. What is the most likely associated gastrointestinal lesion in this condition?

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Diverticular disease

This is adult polycystic kidney disease
Diverticular disease occurs in almost 100% of cases.

Question 23
A 14 year old boy has moderate mental retardation, long facies with an overly prominent jaw, arched palate with speech difficulties, protruding ears, and enlarged, non-tender bilateral testicles. A DNA analysis of this patient’s lymphocytes shows what abnormality?

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CGG repeats

This is Fragile X syndrome
Female carriers may show impaired learning.

Question 24
A 53 year old male drank untreated water from a mountain stream in Kentucky. Two days later he developed abdominal pain and cramps, bloating, and copious foul-smelling diarrhea. He was started on drug therapy by his physician and cautioned against drinking what beverage?
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Alcohol

This is giardiasis and the treating antibiotic is metronidazole
Alcohol consumed within 3 days of metronidazole use will cause severe vomiting.

Question 25
A 78 year old women falls onto her outstretched right hand and suffers a proximal humeral fracture. On exam post trauma, what is the most likely neurological deficit secondary to her fracture?

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Inability to abduct her right shoulder

This is an axillary nerve injury
The axillary nerve supplies motor to the deltoid muscle that is used in abduction of the shoulder.

Question 26
A 34 year old woman stranded in a refugee camp with near starvation develops dermatitis on her face, neck, and the dorsum of her hands and feet and also develops chronic diarrhea and mental status changes. What two elements missing from her diet most likely caused these symptoms?
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Vitamin B3 (niacin and tryptophan)

This is pellagra
Niacin can be synthesized from tryptophan. The three D’s of pellagra are dermatitis, diarrhea, and dementia.

Question 27
An 18 year old male falls asleep in his running car by the side of the road. When the police stop two hours later, the patient has agonal breathing a bright red cherry color to his skin. Which molecule in the body has an extremely high affinity for the causative substance in this case of hypoxic injury?

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Hemoglobin
This is carbon monoxide poisoning.
Hemoglobin has an affinity for carbon monoxide that is 200 times greater than that for oxygen.

Question 28
A 29 year old female is having her gallbladder removed. Shortly after induction of general anesthesia she develops a tachycardia to 160 beats per minute, a fever to 105 F, hypotension, and an obstructive endotracheal tube due to a clenched jaw. What intracellular substance has a striking increase in this condition?

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Calcium

This is malignant hyperthermia.
Other signs and symptoms of malignant hyperthermia:
Increased muscle metabolism
Rhabdomyolysis
Acidosis

Question 29
A 38 year old pre-menopausal female developed breast cancer and was given a chemotherapy agent which caused myelosuppression, hair loss, and decreased cardiac ejection fraction. What is the cellular mechanism of action of this drug?

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DNA breakage and decreased replication of tumor cells via
Non-covalent intercalation.
This is adriamycin (doxorubicin)

Question 30
A 74 year old man was taken to the operating room due to an enlarging bulge that occurred with effort in his right groin. In the operating room the surgeon noted the lesion occurred just medial to the inferior epigastric vessels. What anatomic space did the lesion occupy?

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Hesselbach’s triangle
This is a direct inguinal hernia and occurs when bowel contents bulge through Hesselbach’s triangle.

Question 31
A 6 month old infant is sent home from daycare with respiratory difficulty which progresses to bronchiolitis and pneumonia. Is the causative agent a DNA or RNA virus and an enveloped or nucleocapsid virus?

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RNA enveloped virus
This is respiratory synctyial virus (RSV)

Question 32
A 52 year old woman develops increasing dementia. Her mother developed the same symptoms at age 51 years. Her work-up indicates she has the PS-1 and PS-2 genes. What histological lesion is very likely to be found in the cytoplasm of her brain pyramidal cells?

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Neurofibrillary tangles

This is early onset Alzheimer’s disease.
PS-1 and PS-2 are the presenilin genes found in 50% of early onset, autosomal dominant Alzheimer’s.

Question 33
An 8 year old boy developed a “sore throat” and was culture positive for group A beta hemolytic streptococci on throat swab. He did not receive any treatment for this and 3 weeks later he developed carditis, polyarthritis, and fever. What is the name of the diagnosing criteria for this condition?

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Jones criteria

This is rheumatic fever. Diagnosis requires presence of two major and one minor or one minor and two major criteria.
Major criteria
Carditis (35%)
Polyarthritis (75%)
Chorea (5%)
Erythema marginatum (10%)
Erythema nodosum (10%)
Minor criteria
Fever
Arthralgia
Increased ESR or C-reactive protein
EKG changes (especially prolonged PR interval)
Preceeding attack of rheumatic fever

 

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